1. Ahlfors, L.V., Grunsky, H.: Über die Blochsche Konstante. Math. Z. 42(1), 671–673 (1937)
2. Albert II, B.: Landau’s constant, and extremal problems involving discrete subsets of $${\mathbb{C}}$$. In: Havin, V.P., Nikolski, N.K. (eds.) Linear and Complex Analyis Problem Book 3, Part 2, Number 1574 in Lecture Notes in Mathematics, vol. 18, pp. 404–407. Springer, Berlin (1994)
3. Albert II, B.: A minimum problem for heat kernels of flat tori. Extremal Riemann Surfaces (San Francisco, CA, 1995), Volume 201 of Contemporary Mathematics, pp. 227–243. American Mathematical Society, Providence (1997)
4. Baernstein II, A., Eremenko, A., Fryntov, A., Solynin, A.: Sharp estimates for hyperbolic metrics and covering theorems of Landau type. Ann. Acad. Sci. Fenn. Math. 30, 113–133 (2005)
5. Baernstein II, A., Vinson, J.P.: Local minimality results related to the bloch and landau constants. In: Peter, D., Juha, H., Brad, O., Bruce, P. (eds.) Quasiconformal Mappings and Analysis: A Collection of Papers Honoring F.W. Gehring, pp. 55–89. Springer, New York (1998)